Events refactor in Android session based capturing.

webrtc/api/android/java/src/org/webrtc/CameraSession.java

 /*
  *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.webrtc;
 
 public interface CameraSession {
+  // Callbacks are fired on the camera thread.
   public interface CreateSessionCallback {
     void onDone(CameraSession session);
     void onFailure(String error);
   }
 
+  // Events are fired on the camera thread.
+  public interface Events {
+    void onCameraOpening();
+    void onCameraError(CameraSession session, String error);
+    void onCameraClosed(CameraSession session);
+    void onByteBufferFrameCaptured(CameraSession session, byte[] data, int width, int height,
+      int rotation, long timestamp);
+    void onTextureFrameCaptured(CameraSession session, int width, int height, int oesTextureId,
+      float[] transformMatrix, int rotation, long timestamp);
+  }
+
   /**
    * Stops the capture. Waits until no more calls to capture observer will be made.
    * If waitCameraStop is true, also waits for the camera to stop.
    */
   void stop();
 }